In order to improve traveling safety, an apparatus has been proposed which calculates a risk potential around a vehicle. For example, Patent Literature 1 discloses an apparatus in which a camera captures an image, a preprocessing unit processes the image, and a pedestrian recognition unit recognizes a pedestrian from the input image. In the apparatus disclosed in Patent Literature 1, a priority setting unit sets priority on the basis of the size, position, and movement state of a pedestrian image in the input image. In the apparatus disclosed in Patent Literature 1, a calculation order determining unit determines the order of a distance calculation process by a calculation unit such that the distance is sequentially calculated from the pedestrian with high priority.